How can I tell if Cloudflare is caching my site or a specific file?

To test if your site or a specific resource is being cached, use webpagetest.org. After you enter a URL and run a test, you can review the details page. If Cloudflare is caching, the response headers show the following:

CF-Cache-Status: HIT

If you have access to a terminal or command line window, you can also check a particular resource by using this command: